A New Sheet Metal Forming Technology Of Solid Granule Medium Bending Process

Springback is a very common and knotty problem in bending process, this paper adopts solid particles medium process for U and V shape bending, in order to improve springback problem. Solid granules are characteristic of favorable fluidity and almost non-condensability of solidity,solid particles medium process is one category of soft tool forming technologies, which use solid particles as load transfer medium. Making analysis to solid granules bending process with finite element simulation, finite element numerical simulation results show that new process can effectively reduce springback angle and relative bending radius.During the research process, U and V shape bending of 4mm thick Aluminum blank test has been completed with the self– designed solid particles medium bending die set. By changing the diameters of solid particles、reverse pressures and die clearances etc,it obtains a great deal of test data. Results show that the new technology of solid granules bending process is better than traditional rigid mold bending process, the springback angle of U shape bending reduce to 1.8°, the spring angle of V shape bending reduce to 1.65°, and relative bending radius is up to 0.25. It also obtains the influence of different diameter granules and different reverse pressure to springback, and analysis the cause. While in the same reverse pressure, the bigger steel ball granules diameter, the worse surface quality, the smaller springback angle; in the same steel ball granules diameter, the bigger reverse pressure, the worse surface quality, the smaller springback angle.This subject extends application scope of solid particles medium process, and proposes a new process for improving spingback problem of bending process.